Oil addend



Patented May 17, 1949 Franklin M. Watkins, Chicago, Ill., assignor toSinclair Refining Company, New York, N. Y., a corporation of Maine NoDrawing. Application November 29, i945,

Serial No.'631,771

This invention relates to a method for inhibiting the sulflding ofmetallic copper by elemental sulfur present compositions comprisinginhibitors employed in method.

Because of its corrosive action, particularly with respect to copper,the presence of even very small amounts of elemental sulfur in petroleumoils, including insecticide base kerosene, naphtha, gasoline, hydraulicoils, medicinal oils, lubricating oils etc, is sometimes highlyobjectionable. While a number of processes are available for the removalof sulfur from such oils, these processes are only partially effectivein many cases, supplemental treatment being frequently required to meetproduct specifications.

I have discovered that a small amount of a hydrocarbon hydroperoxidewhen added to a petroleum oil containing elemental sulfur inactivatesthe sulfur so that it will not react with copper metal. oxides Iparticularly prefer tertiary-butyl hydroperoxide. As little as 0.006 percent of this hydroperoxide ona volume basis is sufiicient in most cases.Apparently inhibiting or inactivating action of. the tertiary-butylhydroperoxide is not due to reaction between it and the sulfur since thehydroperoxide is eliective immediately upon addition to the oil andsince agitating the oil under condtions which would remove uncombinedperoxide by evaporation results in immediate respetroleum oils and thethe practice of the toration of the corrosive property of the oil.

The tertiary-butyl hydroperoxide is quite permanent in its action. Thus,samples of this hydroperoxide in kerosene containin elemental sulfur asan impurity, after storage at room temperature for nearly six months didnot corrode copper strips kept suspended in the samples for three hoursat 212 F.

For a peroxide, tertiary-butyl hydroperoxide is unusually stable asshown by the fact that it can be distilled under reduced pressurewithout Gravity, API

Flash point, F. 300

2 Claims. 25252) in petroleum oils and embraces 2 Fire point, "F 845Viscosity -40 F. Cs 4867.6 Viscosity 100 F. Cs 12.0 Viscosity 210 F. Cs-Q. 2.95 Cloud point, F. Below -'m Pour point, "F Below '70 Acid No.0.00 Saponification N 0.29 Aniline point, F 191.5 Sulfur 0.03 Corrosioncopper strip Negative From the table, in which the percentage sulfur isby weight and the percentage inhibitor by volume, it will be seen thatwhile tertiary butyl hydroperoxide gives protection in lowerconcentration than para-cymene hydroperoxide, the latter Of thehydrocarbon hydropercompound is effective at 0.02% concentration whichis not true of acetyl peroxide, tertiarybutyl perbenzoate, lauroylperoxide, and benzoyl peroxide.

Table I Copper Strip Corrosion-Federal Specification VV-L-79l, Meth- 0d530.31

Base 0i1 +0.004% Elementary Sulfur... Positive. Base O1l+0.004%Elementary Sulfur-+0.02% Negative.

Tertiarybutylhydroperoxide. Base Oi1+0.004% Elementary Suliur+0.0l% Do.

Tertiarybutylhydroperoxide. 4 i Base Oil+0.004% Elementary Sulfur+0.006%Do.

Tertiarybutylhydroperoxide. Base 0il+0.004% Elementary Snliur+0.004%Positive.

Tertiarybutylhydroperoxide. Base 0il+0.004% Elementary Suliur+0.020%Negative.

Para-cymenehydroperoxide. Base Oil+0.004% Elementary Suliur+0.0l0%Positive.

Para-cymenehydroperoxide. Base Oil+0.004% Elementary Suliur+0.006% Do.

Para-cyrnenehydroperoxide. Base 0il+0.004% Elementary Sulfur+0.020% Do.

Acetylperoxide. Base Oil+0.004% Elementary Snlfur+0.0l0% Do.

Acetylperoxide. Base Oil+0.004% Elementary Sulfur+0.006% Do.

Aceteylperoxide. Base Oil+0.004% Elementary S11lfur+0.020% Do.

Tertiarybutylperbenzoate. Base Oil+0.004% Elementary Suliur+0.0l0% Do.

Tertiarybutylperbenzoate. Base Oil+0.004% Elementary Suliur+0.006% Do.

Tertiarybutylpcrbenzoate. Base Oil+0.004% Elementary Suliur+0.02% Do.

Lauroylperoxide. Base Oil+0.0o4% Elementary Suliur+0.01% Do.

Lauroylperoxide. Base Oil+0.004% Elementary Suliur+0.006% Do.

Lauroylperoxide. Base 0il+0.004% Elementary S11lfur+0.02% Do.

Benzoylperoxide. Base Oi1+0.004% Elementary Suifur+0.0l% Do.

Benzoylperoxide. Base Oil+0.004% Elementary Suliur+0.006% Do.

Benzoylperoxide.

My invention is further fllustrated by the following examples, showingthe application of my preferred inhibitor to various petroleum stocks:

amaave Example 1 The oil involved in this test was a hydraulic oilcorrosive to copper. as shown by the Federal test identified in Table I,and having the other properties indicated below:

Gravity, API 33.0 Flash point, F 200 Fire point, "P 215 Viscosity 100 F.Cs 3.12 Viscosity 210 F. Cs 1.22 Pour point, F Below --70 NeutralizationNo 0.00 Aniline point, F 154.8

After the addition of two drops of tertiary-butyl hydroperoxide to 100cc. of the oil, it successfully passed the test.

Example 2 0.004% sulfur by weight was added to a second hydraulic oilwhich had tested non-corrosive to copper. The oil tested positivefollowing addition of the sulfur but repassed the test when 0.006% byvolume of tertiary-butyl hydroperoxide was added. The inspection on thisoil was as follows:

Gravity, API

Flash point, "F 305 Fire point, F 340 Viscosity 100 F. Cs 11.39Viscosity 210 F. Cs 2.63 Pour point, F -65 Neutralization No 0.00Aniline point, F 191.1

Example 3 The oil here involved was an insecticide base oil corrosive tocopper and having the following other characteristics:

Gravity, API 46.4 Initial B. P., F 358 10% 380 50 416 90 455 End point495 The oil was rendered non-corrosive by the addition of 0.006% byvolume of tertiary-butyl ydroperoxide.

Example 4 0.004% sulfur by weight wasadded to lubricating oil stockwhich had tested non-corrosive to copper. The oil tested positivefollowing addition of the sulfur but when' 0.20% by volume oftertiary-butyl hydroperoxide was added it repassed the test. In the caseof lubricating oils an amount of the inhibitor greater than 0.006%appears necessary for adequate protection. This particular lubricating011 stock showed the following inspection:

Gravity, API- 25.0 Flash point, "F 285 Fire point, "F 315 Viscosity 100F.,Cs... 8.07

Viscosity 210 F. (38-..-..1. 2.09

Four point, '1' Below Neutralization No 0.00

Aniline point, F 140.0

Copper strip corrosion Negative Example 5 To a compounded hydraulic oilcontaining an isobutylene polymer (Paratone) as a viscosity indeximprover was added 0.004% by weight 01' sulfur. When subsequentlysubjected to the copper corrosion test the oil tested positive. Theresult upon re-testing after addition of 0.01 per cent tertiary-butylhydroperoxide was negative. This test is significant as showing thatviscosity index improvers of'the type of Paratone do not adverselyeffect the action of the hydroperoxide.

Example 6 0.004% by weight of sulfur was added to a sample of re-runalkylate stock which had tested non-corrosive to copper. The sampletested positive following addition of the sulfur but when 0.04%oftertiary-butyl hydroperoxide was added it repassed the test. Theinspection on the alkylate stock was as follows:

Gravity, API 70.4 Initial B. P., F 10% 50 221 90 288 End point 346Example 7 tertiary-butyl hydroperoxide and para-'cymene hydroperoxidesufllcient to inhibit such corrosion.

2. A petroleum oll,'norma1ly corrosive to copper by reason of itscontent of sulfur, containing an amount of tertiary-butyl hydroperoxidesufilcient to inhibit such corrosion.

FRANKLIN M. WATKINS.

REFERENCES CITED The following references are of record in the file ofthis patent:

I UNITED STATES PATENTS Number Name Date 2,093,008 Egerton Sept. 14,1937 2,249,340 Wilson July 15, 1941 2,403,771 Vaughan et a]. July 9,1946 FOREIGN PATENTS Number Country Date 542,834 Great Britain Jan. 29,1942

